Antioxidant effects of Genkwa flos flavonoids on Freund׳s adjuvant-induced rheumatoid arthritis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Genkwa flos (Daphne genkwa Sieb. et Zucc.), a Chinese herbal medicine, has been traditionally used for over two thousand years in China for inflammation related symptoms, including joint pain. To evaluate the antioxidative effects of flavonoid aglycones (FA) isolated from Genkwa flos on adjuvant arthritis in rats and to identify the relationship between antioxidant potential and whole blood viscosity (WBV).

MATERIALS AND METHODS: FA compounds were identified using LC-MS and the content was assayed by HPLC. Arthritis was induced by an intradermal injection of Freund׳s complete adjuvant in the footpad. The effects of FA on paw volumes, secondary arthritis scores, histopathology of joints, and body and organ weights were measured. The antioxidant effects of FA and WBV were determined.

RESULTS: LC-MS analysis showed that the FA contained four major compounds: luteolin, apigenin, hydroxygenkwanin and genkwanin. FA significantly decreased paw edema, arthritis scores, and weight loss. These observations were consistent with the reduction of oxidative stress and the improvement of the WBV.

CONCLUSION: FA significantly decreased arthritis in a rat model through antioxidant and hemorheological modulatory mechanisms. The Genkwa flos flavonoids may have clinical potential for the treatment of rheumatoid arthritis.